So, have you read the book? Just seems quite a basic question to be honest. It's very good, but I can see ya gonna have trouble if you're trying to write an essay on it without having read it. That said, I did do that once for a friend doing English.
Ya know, totalitarianism, they use censorship, mind-games and indoctrination, propaganda, control of sharing of ideas by newspeak, etc.
Quick Google yields these which might are a bit more indepth: